Production of biodiesel and other valuable chemicals from wastewater treatment plant sludges

Abstract

A process for producing biodiesel has been invented by first extracting lipids from the sludges generated during primary and / or biological treatment of municipal, agricultural, and industrial wastewaters using primary, secondary, and tertiary treatments followed by the transesterification of the extracted lipids using transesterification conversion into alcohol-based esters. The resulting products from this process include biodiesel, glycerol, lipid-free proteins, various other useful chemicals and an aqueous-based substrate well suited for optimized digestion within subsequent biological digestion (either aerobic or anaerobic). The lipids extracted from the sludges containing high levels of microorganisms are phospholipids which can also be directly used as lecithin. The extraction of the lipids from the sludges will be performed using chemical extraction techniques with the transesterification of the extracted lipids accomplished using basic, acidic, and / or a combination of the two transesterification techniques.

Description

[0001] This application claims priority from U.S. Provisional Application Ser. No. 60 / 507,698 filed Oct. 2, 2003. The entirety of that provisional application is incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention involves the production of numerous valuable chemicals using an innovative processing of sludges generated during primary, secondary and / or tertiary treatment of municipal, agricultural, and industrial wastewaters. [0004] The produced chemicals include lipids and biodiesel (a renewable replacement to petroleum-based diesel), lecithin (a commercial nutrient and processing “building-block chemical” typically produced from eggs and soy oil), glycerol (a widely used chemical feedstock in many industrial processes), and a by-product that is much more digestible than typical influents to digestion processes at wastewater plants, due to the removal of the lipid fraction, which in turn will increase the rate and exten...

AI Technical Summary

Benefits of technology

[0012] In addition to providing a novel process for extracting useful chemicals from such waste products, the process will serve to reduce environmental threats and offer operators of wastewater producing facilities an unexpected source of income rather than a disposal and possible liability expense from such waste products.

[0019] It is another object of the present invention to provide a method of producing biogas by treatment of sludges, which are rendered easily digested, the sludges being obtained from wastewater treatment facilities.

[0022] It is another object of the present invention to provide a lipid free dried sludge that can be thermally converted into condensable oils or pyrolyzed into biooils.

Problems solved by technology

All of these waste streams pose environmental threats and their management represents government regulatory and economic challenges to their respective facility operators.

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